Gillardite

Greetings everyone; this month we will examine one of the rare minerals from Western Australia. The mineral species is Gillardite; which is a copper nickel chloride hexahydrate with the chemical formula of: Cu3NiCl2(OH)6. The type locality for this rare mineral is the 132 North Mine, Widgiemooltha, Western Auastralia. The 132 North Mine is an open pit nickel mine located 4 km south-west of Widigiemoothla and 80 km south of Kalgoorlie. Gillardite is a relatively new mineral species having been approved in 2007. The mineral is named for Professor D. Gillard in recognition of his contributions to the field of inorganic chemistry. I obtained some specimens form a micromounter friend who lives in Western Australia. In terms of physical properties, Gillardite is dark green in color and is transparent (Very pretty crystals in the microscope). The mineral crystallizes as numerous individual crystals or clusters of crystals. Some of the crystal clusters I have observed are in the form of rosettes. Gillardite crystallizes in the Trigonal system, Rhombohedral class and manifests as triangular shaped crystals. The mineral is relatively soft with a hardness of only 3 so care must be exercised when handling the specimens. The specimens I have also feature another rare mineral, Hydrohonessite which is a nickel, iron sulfate hydroxide septa hydrate with the chemical formula of Ni6Fe2(SO4)(OH)16•7(H2O). This mineral is named for Arthur P. Honess (1886-1942), Pennsylvania State University. Individual crystals are indistinguishable usually forming large masses of rounded nodules. This mineral crystallizes in the hexagonal system with the crystal class undetermined at this time. In terms of physical properties hydrohonessite is yellow to yellow-green in color, opaque and very soft with a harness of only 1 -1.5. Shown below are some photomicrographs of Gillardite on Hydrohonessite from the 132 North Mine in Western Australia. These photomicrographs are all at a magnification of 60X.

Note that these are very rare minerals. I have found only a couple of mineral dealers with these minerals for sale and then at a princely price. They are very attractive specimens and will make a valuable addition to any micromount collection. Until next time may all your skies be blue and all your vugs crystal filled.